Head's up Toronto; if you're looking to swim at any city beaches today to get relief from extreme temperatures, it's best to avoid them all completely.

Following Monday's heavy rains, elevated levels of bacteria (mainly E.coli) have been reported across Lake Ontario, prompting the city to issue a safety warning.

Stay safe and avoid swimming in the lake for at least 48 hours after heavy rainfall. Find out why: https://t.co/3KHI0r9Oua pic.twitter.com/1I3k0Wk7vE

— City of Toronto (@cityoftoronto) July 18, 2022

"It can be unsafe to swim, even at designated swimming beaches for 48 hours after heavy rainfalls," read the notice.

Bacteria elevation can be caused by a number of things including stormwater runoff, sewer overflow, spills and illegal dumping, accidental cross connection of pipes and polluted water enter local waterways from streams and rivers.

According to the city's water beach quality page, four beaches are still unsafe to swim including; Marie Curtis Park East Beach, Centre Island, Kew Balmy and Bluffer’s Beach.

All four of these beaches have elevated amounts of E.coli, which pose a serious health risk to swimmers (think vomitting, nausea..etc.)

Though the rest of the city's six beaches currently have safe swimming conditions, tonight's anticipated thunderstorms and showers may just push them over the edge again.

It takes a while to collect, transport and eventually test the samples for E.coli, around a day or more, so these conditions may have already changed.

Any result, it's best to skip the beaches altogether today and take a dip at the pools that have extended hours tonight for this atrocious heat wave.